Gray, Darren J.Thrift, Aaron P.Williams, Gail M.Zheng, FengLi, Yue-ShengGuo, JiagangChen, HonggenWang, TianpingXu, Xin JiangZhu, RongZhu, HongqingCao, Chun LiLin, Dan DanZhao, Zhen YuanLi, Robert S.Davis, George M.McManus, Donald P.2015-11-012015-11-011935-2735http://hdl.handle.net/1885/16192BACKGROUND Schistosoma japonicum is a major public health concern in the Peoples' Republic of China (PRC), with about 800,000 people infected and another 50 million living in areas at risk of infection. Based on ecological, environmental, population genetic and molecular factors, schistosomiasis transmission in PRC can be categorised into four discrete ecosystems or transmission modes. It is predicted that, long-term, the Three Gorges Dam (TGD) will impact upon the transmission of schistosomiasis in the PRC, with varying degree across the four transmission modes. METHODOLOGY/PRINCIPAL FINDINGS We undertook longitudinal surveillance from 2002 to 2006 in sentinel villages of the three transmission modes below the TGD across four provinces (Hunan, Jiangxi, Hubei and Anhui) to determine whether there was any immediate impact of the TGD on schistosomiasis transmission. Eight sentinel villages were selected to represent both province and transmission mode. The primary end point measured was human incidence. Here we present the results of this five-year longitudinal cohort study. Results showed that the incidence of human S. japonicum infection declined considerably within individual villages and overall mode over the course of the study. This is also reflected in the yearly odds ratios (adjusted) for infection risk that showed significant (P<0.01) downward trends in all modes over the follow-up period. CONCLUSIONS/SIGNIFICANCE The decrease in human S. japonicum incidence observed across all transmission modes in this study can probably be attributed to the annual human and bovine PZQ chemotherapy. If an increase in schistosome transmission had occurred as a result of the TGD, it would be of negligible size compared to the treatment induced decline seen here. It appears therefore that there has been virtually no immediate impact of the TGD on schistosomiasis transmission downstream of the dam.The work presented in this publication was funded by the National Institutes of Health (NIH) under the Tropical Medicine Research Centre (TMRC) scheme; The Wellcome Trust (WT); and the National Health and Medical Research Council (NHMRC), Australia. Darren Gray is an Australian Research Council (DECRA) Fellow; Yue-Sheng Li is a Howard Hughes Medical Institute International Research Scholar and an Australian Research Council Future Fellow; Donald McManus is a NHMRC (Australia) Senior Principal Research Fellow.9 pages© 2012 Gray et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.adolescentadultagedanimalsanthelminticscattlechildchild, preschoolchinacohort studiesdrug therapyfemalehumansincidencelongitudinal studiesmalemiddle agedpraziquantelprospective studiesschistosoma japonicumschistosomiasissentinel surveillanceyoung adult2012-04-1010.1371/journal.pntd.00015882015-12-10